Occurrence and Flow Mechanism of Flashflood
| Project/Area Number |
06452362
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
林学
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| Research Institution | KYOTO UNIVERSITY |
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Principal Investigator |
MIZUYAMA Takahisa Kyoto University, Graduate School of Agriculture, Professor, 農学研究科, 教授 (00229717)
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| Co-Investigator(Kenkyū-buntansha) |
KOSUGI Ken'ichirou Kyoto University, Agriculture, Graduate School of Agriculture, Instructor, 農学研究科, 助手 (30263130)
OHTE Nobuto Kyoto University, Graduate School of Agriculture, Lecturer, 農学研究科, 講師 (10233199)
KOBASHI Sumiji Kyoto University, Graduate School of Agriculture, Professor, 農学研究科, 教授 (40026604)
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| Project Period (FY) |
1994 – 1996
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| Project Status |
Completed (Fiscal Year 1996)
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| Budget Amount *help |
¥7,500,000 (Direct Cost: ¥7,500,000)
Fiscal Year 1996: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1995: ¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1994: ¥4,800,000 (Direct Cost: ¥4,800,000)
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| Keywords | flahflood / mountain torrent / debris flow / landslide dam / sabo / 土砂災害 / パイプフロー / 流量観測 / 実験 |
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| Research Abstract |
Debris flow is a major cause of sediment related hazards in mountain streams. Typical debris flow where sediment grains are evenly dispersed throughout the entire depth has been studied the most. The criteria for identifying debris flow prone torrents are based on the research results from typical debris flow. Debris flow that is not typical, so called immature debris flow where a layr of water is seen near the surface may occur and cause hazards smilar to those of the typical debris flow. Here we call the immature debris flow a flashflood. We think flashfloods more commonly cause debris flow hazards than the typical debris flow. Some examples of flashflood disasters are introduced first. The occurrence conditions and flow mechanisms are studied through flume experiments. The domain of the occurrence of the flashflood coincides with that of immature debris flow or of the intermediate flow happening between bedload and debris flow. Next, the change of flow when the flashflood arrives at the channel with a reduced gradient is also observed through flume experiments. The change of overall sediment concentraion is measured. The results are useful and in fact necessary for building simulation models of depositional processes of debris flow on alluvial fans.
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Report
(4 results)
Research Products
(7 results)
